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Algebra Difficulty 2.3 Junior Find the answer

The average (mean) of two numbers is 7. One of the numbers is 5. What is the other number?

A number or a short expression. Spacing and $ signs are ignored.

Solution

Since the average of two numbers is 7, their sum is 2imes7=142 imes 7=14. Since one of the numbers is 5, the other is 145=914-5=9.

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